Telephone instrument base



FIG. 1 is a perspective view of a telephone instrument base, showing my new design;

FIG. 2 is a side elevational view thereof, the opposite side being a mirror image of the side shown;

FIG. 3 is a front elevational view thereof; and

FIG. 4 is a rear elevational view thereof. 

The ornamental design for a telephone instrument base, as shown. 